As sementes de guaraná (Paullinia cupana Kunth, Sapindaceae) são utilizadas como estimulante e os principais constituintes químicos são as metilxantinas e os taninos, tais como catequina e epicatequina. Este trabalho teve por objetivo investigar um método por cromatografia líquida de alta eficiência (CLAE) para quantificar, simultaneamente, cafeína, teofilina, teobromina, catequina e epicatequina em pó de guaraná. Os valores obtidos foram comparados com os resultados encontrados no método espectrofotométrico da Farmacopéia Brasileira IV ed. Pelo método cromatográfico, os teores de metilxantinas e taninos totais foram de 4,04% e 1,48%, respectivamente. Os teores de metilxantinas e taninos totais, obtidos pelo método espectrofotométrico, foram de 4,88% e 4,05%, respectivamente. Acredita-se que, nas condições experimentais empregadas, o método espectrofotométrico não foi específico, quantificando outras substâncias fenólicas presentes no guaraná. Portanto, sugere-se o emprego desse método cromatográfico no controle de qualidade do guaraná em pó, por ser preciso, sensível, específico e rápido.

The seeds of Paullinia cupana Kunth, Sapindaceae, are used as a stimulant and the main chemical constituents are the methylxanthines and tannins, as catechin and epicatechin. This study aimed to investigate a method by high performance liquid chromatography (HPLC) to quantify both caffeine, theophylline, theobromine, catechin and epicatechin in powdered of P. cupana. The values obtained were compared with the results of the spectrophotometric method of the Brazilian Pharmacopoeia IV ed. For the chromatographic method, the levels of methylxanthines and total tannins were 4.04% and 1.48%, respectively. The levels of methylxanthines and total tannins obtained by the spectrophotometric method, were 4.88% and 4.05%, respectively. It is believed that, under our experimental conditions, the spectrophotometric method was not specific and quantified others phenolic substances present in the P. cupana. Therefore we suggest the use of this chromatographic method in quality control of P. cupana powder, to be accurate, sensitive, specific and fast.

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5 - xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5 - xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.

O intuito deste trabalho de pesquisa foi obter parâmetros de controle de qualidade para a identificação da matéria-prima vegetal (folha) de Pimenta pseudocaryophyllus (Gomes) L. R. Landrum - Myrtaceae que ocorre no cerrado brasileiro. Para tanto foram coletadas amostras em Minas Gerais - Brasil e no Distrito Federal - Brasil e as exsicatas foram depositadas no Herbário da UFG n. UFG-27.159 e no Herbário Ezechias Paulo Heringer n. 21.745-0, respectivamente. Parte desse material botânico foi preparada para análises macro e microscópicas. Outra parte foi seca, triturada e usada para a triagem fitoquímica. O estudo mostrou que as folhas de P. pseudocaryophyllus são hipoestomáticas, têm grande quantidade de tricomas unicelulares na superfície abaxial, têm cavidades secretoras contendo compostos lipídicos e as células epidérmicas possuem paredes celulares espessas. Na triagem fitoquímica foram detectados compostos fenólicos, taninos e flavonóides. Os taninos foram dosados por diferentes métodos envolvendo reações colorimétricas e de precipitação com proteínas. Os diferentes resultados verificados chamam a atenção para a necessidade de se especificar o método utilizado juntamente com o limite mínimo de taninos totais estabelecido. Os resultados obtidos configuram-se como importantes parâmetros para o controle de qualidade da matéria-prima vegetal e denotam que a espécie em estudo possui um importante potencial fitoterápico que merece ser investigado em estudos farmacológicos e toxicológicos.

The goal of this research was to obtain quality control parameters for the identification of the plant drug of Pimenta pseudocaryophyllus (Gomes) L. R. Landrum that occurs in Brazilian savannah. So, two samples were collected, one in Minas Gerais state - Brazil, and the other one in Brasilia city - DF - Brazil, and the vouchers were deposited in the UFG Herbarium code number UFG-27159 and Ezechias Paulo Heringer Herbarium code number 21745-0, respectively. Part of the botanical material in both samples was prepared for microscopic analysis. The other one was air-dried, crushed to powder and used for phytochemical screening. The study has shown that P. pseudocaryophyllus leaves are hypostomatic, there are abundant unicellular trichomes in abaxial surface, there are secretory cavities with oily content and epidermal cells have thick wall. Tannins, phenolic compounds and flavonoids were detected in the phytochemical screening. The tannins had been quantified by different methods involving colorimetric and protein precipitation reactions, getting different results. This fact calls the attention for the necessity of specifying the method used together with the minimum tannins limit established. The results configure as important parameters for the quality control of the plant material and denote that the species in study take an important potential as herbal medicine that it deserves to be investigated in pharmacologic and toxicologic studies.